1. Field of the Invention
The present invention relates to an activating device for opening and closing the opening faces of various kinds of containers by turning the covers of the containers such as vacuum chambers.
2. Related Art
As disclosed in JP-A-10-89482, the related art activating structure of a cover for a vacuum chamber is as shown in FIG. 8, for example. More specifically, the cover 2 of a vacuum chamber 1 is supported by cover arms 3 (long) and cover arms 4 (short) forming a link mechanism, and the open-and-close driving is transmitted from a motor 6 on a motor driving plate 5 via worm gears (not shown), worm wheels (not shown), drive wires 7 and bevel gears 8.
Further, the whole drive mechanism for opening and closing the cover 2 is located on the motor driving plate 5 and arm supporting bases 9 on the right and left and is made movable vertically by slide bearings 10 and a slide bearing 12 supported by a cylinder supporting metal fitting 11. A cylinder 13 for vertically sliding these component parts is mounted to the cylinder supporting metal fitting 11 fixed to the chamber 1.
The operation of closing of the cover in the activating structure of the cover for the vacuum chamber with the cover 2 opened as shown by an imaginary line in FIG. 8 is performed as follows. When the motor 6 is driven, the rotary motion is reduced by the worm gears and the worm wheels and the reduced rotary motion is divided right and left. When the rotary motion is given to the cover arms (long) 3 on the right and left sides by the drive wires 7 and the bevel gears 8, respectively, the cover arms (short) 4 also rotate accordingly. The cover 2 is moved without parting from the chamber 1 by long and short arm mechanisms and gradually so closed as to form a gap where the contact surface of the cover 2 and the surface of the chamber are set parallel to each other. Subsequently, the whole cover driving mechanism on the motor driving plate 5 and the right and left arm supporting bases 9 as well as the cover 2 coupled to the cover driving mechanism are descended by the suction force of the cylinder 13, so that the cover 2 is closed by uniform pressurizing force.
The related art has posed the following problem because it is characterized by the aforementioned arrangement and operation.
The related art activating structure of a cover for a vacuum chamber as disclosed in JP-A-10-89482 is equipped with the arm link mechanism in which two kinds of cover arms including the long and short cover arms 3 and 4 are fixed to the vacuum chamber 1 simultaneously with the cylinder driving mechanism comprising the motor 6, the worm gears, the worm wheels and the cylinder 13 for use in turning and moving the cover when the cover 2 is opened and causing the arm link mechanism together with the cover 2 to descend immediately before the cover 2 is closed. Consequently, the problem is that the apparatus tends to become large in scale and complicated in structure, which results in an increase in the installation space and poor drive transmission efficiency in the operation of the apparatus. Moreover, since the open-and-close device for the cover is provided on both sides of the vacuum chamber 1, the position of a gateway used for receiving products such as a liquid crystal material and normally opened to the side of the vacuum chamber 1 is restricted.
In the related art without supporting the cover 2 in a flexible floating condition with respect to the arms, it is needed to make an actual thing positioning adjustment among the surface of the vacuum chamber 1, the cover 2 and the open-and-close device for the cover in order that a seal member and the cover located on the surface of the vacuum chamber are uniformly pressurized. Driving the cover to turn is difficult to control delicately and when the cover 2 is closed onto the vacuum chamber 1, for example, the opening face of the vacuum chamber 1 and the cover may induce a slip-off phenomenon and an overload as well as an impact may also be applied to the opening face of the vacuum chamber 1. Consequently, the problem in this case is that the seal member (O-ring) installed on the opening face of the vacuum chamber 1 may be damaged.